As is well known, RFID readers communicate with either passive or active “tags” that respond to signals emitted by respective RFID readers. Systems including the tags and RFID readers have been used for many years to track inventory and items, even persons, in different types of spaces, such as factories, warehouses, retail establishments, hospitals, marathon races, and the like.
As mentioned, the tags may be either passive or active. Passive tags are tags that do not carry a separate power supply, but instead derive their power from the energy of the signals received from RFID readers. Conversely, active tags are tags equipped with separate power supplies, such as batteries, solar cells or the like. An RFID reader may emit a signal that triggers an RFID tag to send back a response signal carrying the identification (ID) associated with the tag. The RFID reader receives the response signal from the tag and captures the tag ID, for further use according to the particular application of the RFID system.
Regardless of whether the tags are passive tags or active tags, RFID readers can be placed in various locations such as walls, light switches, counter tops, door way scanning devices, ceilings, and the like. One device that is ubiquitous in spaces such as the factor, warehouse, retail establishment and hospital are light fixtures.
It has been suggested to incorporate an RFID reader and the antenna required to receive responses from tags in the space in a light fixture, or even into a light bulb. However, these systems require each RFID-enabled light fixture to have both a suitable antenna and an associated RFID reader, which result in systems that are expensive to implement and include redundant devices.